Thread: Antique Tamahagane razor work in progress

Originally Posted by Jakeonthekob

Wow that is pretty cool! Who was the smith of that katana? Also somewhat a shame the blade hasn't been polished to see the hada, nioi/nie.

Keep in mind that aftet hollow grinding, most of that detail is gone. Nioi etc are surface artefacts

Oh sorry, I should have been clearer. I was referring to the original sword, not your awesome razor blade hehe.

That also brings up another question in my mind. Do you think that the type of lamination could affect your blade? I can't really tell from the pics but perhaps it is made in kobuse lamination? And I think your razor is made with the oldest steel here lol.

Excellent question!
The answer is yes and no

I knew up front that there were different way Japanese swords were laminated. And indeed, this has a big influence in grinding. Although in reality, no matter what type of construction, the top part of the blade is always soft, which means the hollows (will) have differential hardness, which sucks to grind. Especially since I had to do all grinding post HT. Challenging to say the least, considering the blade contact is jumpy and always feels like the wheel of a car slipping in sand and alternating between grip and no grip. From that perspective, the construction does matter.

However, there is 1 constant in all Japanese swords: the edge is hard
As long as you keep the edge of the razor where the edge of the sword was, you are guaranteed to have a razors edge made from good steel, regardless of which exact construction was used.

One important thing to keep in mind is that Japanese sword steel is shallow hardening, so unless you keep the edge where the edge used to be, it is very uncertain whether you can work with the original heat treatment. Technically I could re-do the heat treatment. However, a huge part of the attraction for me to work with a genuine sword, is that the edge you will be shaving with will be the work of the smith who hardened it almost 500 years ago!

Yeah that is pretty awesome. I agree, as long as the hardened steel is where the edge is, you should end up with a good shave anyways.